I used almost exactly the same methodology to bypass my ISP's dialer. Except in my case, I searched for my username rather than a PPP PAP packet since I wasn't sure what authentication scheme was being used. Also, my dialer was PPPoE and not good ol' PPP. A slightly more detailed version of what I did (or at least why I did it) can be found here

Cheers,
cgkanchi

PS: Good work! Though a little more explanation of the concepts involved would be nice.